<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>基本数据类型</title>
</head>
<body>
    <!--
        基本数据类型:
            1. 字符串
            2. 数字
                - 普通数字
                - NaN
            3. 布尔值 （用来判断真假）
                true真、 false假
    -->
    <script>
        let lemon
        let uname = lemon
        let uage = 18
        let ifAge = true
        console.log(uname, uage, ifAge)
    </script>
</body>
</html>